Conventional systems are known for removing fluid such as water or oil from wells where there is an abundant supply of fluid, however, in shallow locations or locations with a low production volume, these systems may not be cost justified. For example, in oil formations 500-1000 feet deep which only produce a few barrels of oil per day, multiple oil wells are often situated close together. Equipment and maintenance costs are often economically prohibitive in these shallow wells.
Furthermore, due to pressure, chemical conditions, and sand and grit in most oil wells the equipment is subject to high breakdown rates and requires frequent maintenance, repair or replacement. Consequently, particularly for a shallow, low production situations, there is a need for inexpensive, low maintenance pumping systems. Prior approaches to this type of pumping system have involved complex controls, sensors and electronics normally lowered into the well. This results in excess complexity, cost and maintenance.
One approach to a pumping system is shown in U.S. Pat. No. 4,653,989 issued to Mason. Mason shows a series of pneumatic displacement chambers connected to an air compressor at the surface of the well, by a single air line. Each chamber is connected to the air line through a motorized valve. A float including a disk shaped magnet, rides up and down in each displacement chamber. When fluid fills the chamber, the float approaches the top and the magnet is detected by a sensor which causes the control system to open the motorized valve connecting the chamber to the air line. Once the motorized valve is open, compressed air forces the fluid into the next chamber, or alternatively, into a holding tank on the surface. As the float approaches the bottom of the chamber, the magnet is detected by a sensor which causes the control system to close the motorized valve connecting the chamber to the air line. The Mason patent additionally teaches that the float be provided with flutes between its lower surface and the internal surface of the chamber to avoid the possibility of the float being used as a valve. The design of the Mason patent is costly and complex, requiring a magnetic sensor system located down hole and a motorized valve in connection with each chamber of the well pump, in addition to other shortcomings.
Another well pump is shown in U.S. Pat. No. 4,050,854 to Hereford et al. The Hereford patent shows a well pump including chambers that are costly and complex, among other disadvantages.
Consequently, there remains a need for a simple, efficient, low cost, low maintenance pumping system with a minimum of electronic components and complexity. The present inventions address these needs.
It is an object of this invention to provide an improved fluid pumping system.
It is a further object of this invention to provide a simple, efficient, low-cost, low-maintenance pumping system.